Effects of multi-layer Ti₃C₂T_x nanosheets on compression strength and abrasion resistance of concrete

Abstract

Concrete is a leader composite material for structural use in buildings, adaptable to all locations and circumstances in view of its properties such as versatility, durability, and performance. MXenes are new two-dimensional (2D) materials that are very promising for applications in many fields due to their layered structure and physicochemical characteristics. Focused on increasing the performance of concrete structures, this work proposed the reinforcement of concrete with the addition of very small amounts (0.02 wt.-%) of MXenes consisting of multi-layer Ti3C2Tx nanosheets to improve compression and abrasion resistance. The reinforced concrete specimens were tested by uniaxial compression tests and rubber-wheel abrasion tests. The results obtained were compared with reference concrete prepared without any added nanosheets. The concrete with MXenes presented higher compression strength (15% higher) in relation to the reference samples after 3 days of molding. After 28 days, the average compression strength was 20.5% higher with Mxenes, but the difference at 28 days was not statistically significant. The rubber-wheel abrasion tests showed a tendency for reduced wear rates with Mxenes, but the difference was statistically significant only for the tests with larger abrasives. Differences in macroporosity of the concretes were not found to justify the improved performance with Mxenes. The main differences due to the Mxenes reinforcement were due a smoother microtopography. It was proposed that the mechanism responsible for obtaining smoother topography with MXenes was related to the lubricious nature of the Ti3C2Tx nanosheets, that can reduce interparticle friction when a transition of the paste flow to the thickening regime occurs, which is governed by boundary lubrication.